💡 Our Technical Review in summary
Summary
- Microsoft has announced the retirement of domain isolated web parts within the SharePoint Framework (SPFx).
- This feature, which allowed web parts to run in a unique domain via an iframe to isolate permissions, is being phased out based on usage data and feedback.
- The retirement follows a two-stage timeline: new tenants will lose access starting April 2, 2025, and existing tenants will see the feature fully removed on April 2, 2026.
- There will be no extensions available beyond the final retirement date.
Impact
- For New Tenants: Starting April 2, 2025, any newly created Microsoft 365 tenants will be unable to use or deploy domain isolated web parts.
- For Existing Tenants: On April 2, 2026, all existing domain isolated web parts will stop functioning and will instead display an error message to end-users.
- Functionality: Custom solutions relying on the specific security boundary provided by domain isolation will fail unless they are converted to standard SPFx web parts.
- API Access: Permissions currently scoped specifically to isolated web parts will no longer be valid once the feature is retired.
Action Required
- Identify Impacted Parts: Navigate to the SharePoint Admin Center, go to the “API access” page, and check for any permissions listed under the Isolated grouping.
- Audit Usage: If isolated permissions are found, use the technical guidance provided by Microsoft to locate the specific solutions and the pages where these web parts are currently deployed.
- Update Web Parts: Developers must modify the source code of impacted web parts to remove domain isolation, effectively converting them into “regular” SPFx web parts.
- Redeploy: Once updated, the solutions must be redeployed to the SharePoint App Catalog and updated on the relevant pages before the April 2, 2026, deadline.
- Review Security: Since regular web parts share the same domain as the page, review the API permissions to ensure they align with your organization’s security posture for standard SPFx deployments.
Microsoft Official Update
Service: N/A
Category: planForChange
Severity: normal
Updated February 2, 2026: This update serves as a reminder that SharePoint Framework domain isolated web parts will retire and stop working in 2 months from now (April 2, 2026).
After careful consideration and extensive review of usage data and feedback Microsoft has decided to retire the domain isolated web parts feature in the SharePoint Framework (SPFx).
[When will this happen:]
- Starting April 2, 2025, domain isolated web parts will be turned off for any newly created tenants.
- Starting April 2, 2026, Microsoft will remove the ability to use domain isolated web parts for existing tenants.
[How this will affect your organization:]
If your organization still uses domain isolated web parts, after the change has rolled out these will render an error message and stop functioning. We recommend customers to update the impacted web parts as regular web parts and redeploy them.
[What you need to do to prepare:]
To understand whether you have installed domain isolated web parts and granted permissions you can verify if the SharePoint admin center API access page contains permissions listed under the Isolated grouping. If you see permissions listed under Isolated then you can use the instructions described on the domain isolated web part retirement page to discover the solutions, their domain isolated web parts and where those web parts are used. This resource will also contain the needed steps to update the web parts to not use domain isolation.
Note: There will not be an option to extend domain isolated web parts beyond April 2, 2026.
Learn more:
